Method of manufacturing carbid and products of same.



glomerate of UNITED STATES PATENT OFFICE.

HERMAN L. H AR'IIEINS TIEPIN, OF CONSTANTINE, MICHIGAN, ASSIGNOR, BY MESNE AS- SIGNMENTS, TO CONTINENTAL INVESTMENT COMPANY, OF DULUTH, MINNESOTA,

A CORPORATION OF MINNESOTA.

. nnrnon or MANUFACTURING omen: Am) r nonucrs or semi.

946,432. No Drawing.

' To all-whom it may co'mem:

'Be it known that I, HERMAN L. HARTEN- s'rm'N, a citizen of the United States, residing at Constantine, in the count Joseph and State of Michigan,

in the Method of Manufacturing Cal-bid and roducts of Same, of which the following is a full, clear, and exact description.

This invention relates to methods of manufacturing carbid and products of same;

and it comprises a method of reducing solid g is-treated by incorporating therein fine preformed carbidj prior to allowing .such

carbid wherein nloltn carbi such as carbid .fines molten carbid to solidify; and it also comsubstantially non-crystalline magma or conpreformed fine fragmentary car-bid cemented by a matrix of set m'olten carbid; all as more fully hereinafter set forth and as claimed.

In the art of making carbids, ularly calcium carbid, the usual practice is to allow the molten carbid after formation to cool and solidify naturally as a body. Ordinarily the carbid is permitted to solidify either in the furnace in which it was formed or in se arate ingot molds, in either case cooling reititively slowly from'the inand partictense temperature at which it is formed and .theexterior of the block or solidifying in bulk. As carbid isa relatively bad conductor of heat, in cooling in' this manner iping, segregation and the like take place, t e ingot or the block of'carbid cooling and solidifying first on its exterior surfaces vwhile the interior remains molten for a relatively longer time. Ingots or blocks so formed are found to be much harder on the exterior than in the and at the center there is usually a cavity or passage; a piping. For some reason, the softer carbid which separates toward the interiorof the block in the stated ordinary process of relatively slow cooling is more efficient in'producing-acet lene than is the relatively harder, first soli ifying carbid on ingot. This superlor carbid of the interipr being relatively soft gives a much greater proportion of-fines than doesthe exterior portion, in reducing interior,

Specification of Letters Patent.

ave in-; vented certain new and useful improvements of carbid a fine grained and segregation,

geneous carbid block or body of uiuforin Patented Jan. 11, 1910.

Application filed February 18,1907. Serial No. 858,014.

the whole mass to they are not well adapted for the ordinary Nor have thetypes of acetylene generator. methods of recovering these fines heretofore proposed been commercially practicable. It' i as been, for instance, proposed to -'utilize this fine dust-like or 'collectin powdered material by it until enou h accumulates and again'su mitting it to t e actionof the electric current in the reducing furnace; that is, it has been proposed to simply melt it down in order to reform block or ingot carhid. But it has been-found that on re-melting such fines, the product obtained is not as good as the original carbid and does notgive as great a yield of acetylene on treatment with water even as did the original as fines.- This is probably due tothe fact that the fines, which expose an inordinately large surface. to the action of the atmosphere, quickly undergo an aerial hydration, carbonatation, and oxidation, which not only destroys a portion of-the carbid but produces' new substances which, on fusing the mass, act upon'the residual Cfllbltl and further diminish its total proportion.

The present invention has for its object the utilization'of these fines and the simultaneous production of a new form of carbid which is ordinary types of calcium carbid. I have found that by incorporating finely powdered carbid as it comes from the crushing andv sizin apparatus into the molten carbid co1ning rom the furnace, a magmais produced which solidifies without the usual piping giving a fine grained homoquality throughout and yielding but a relatively small proportion of. fines on comniinution. In this article preformed solid .carbid fines may be said to-form the aggro gate while the molten carbid forms a matrix or binder therefor. The fines'from the mill are fragments of a broken down crystal aggregate and are sharp-edged and angular practically more efiicient than the so that microscopically the new carbid article displays a sort of concrete of angular particles in a cementing carbid matrix.

in the usual practice of my invention, I first produce molten calcium carbid according to the usual or any suitable manner, allowing the molten product to solidify as usual. in producing calcium carbid the reagents employed may be, as usual, lime or limestone and a carbonaceous material, but the particular reagents are not important so far as the hereindescribed invention is concerned. After producing the solid mass or ingot of carbid,'it is crushed or broken in the usual manner, the fine unmerchantable grains or dust being separated from the granular mercha-ntable carbid as usual and by the usual sizing and sifting means. The fine dust or carbid waste is now stirred into,

. incorporated with or kneaded into a quantity of freshly produced carbid while the latter is in a molten, fluid, semi-fluid or plastic condition.

In practice I may place a quantity of the dustdike waste carbid in the bottom of an ingot mold or other suitable container. and run a portion of the molten carbid thereinto. The molten carbid and the carbid waste are now stirred or mixed together until it goad incorporation is secured, when a further quantity of dust or fines is thrown into the mold, a further supply of the molten carbid cast in and stirred up withthe dust, and so on until the entire quantity of waste carbid'has been taken up and incorporated in the molten or semi-molten mass. furnace may be tapped and the molten carbid allowed to flow continuously into the ingot molds or other receivers; the fines or dust being thrown into thefiowing massor into the molten carbid in the mold from time to time or continuously, as may be desired, the mixture being stirred to cause a good incorporation. The operation may be facilitated by the addition of a small quantity of common salt or sodium chlorid to the molten material, since this acts as a flux and assists in the union of the solid particles with the molten portion of the charge, allowing a more thorough and easier incorporation of the solid and the molten carbid. lrVith an ingot of carbid thus produced, consisting of a magma of preformed dust-like solid parmoles of carbid and a cementing matrix of other carbid, it is found that on cooling the ingot is practically homogeneous throughout, displaying no central piping, sponginess or voids, the presence of the solid carbiddiminishing pro )ortionally to its amount the contractionof the whole body due to the contraction of the liquid carbid. The compound ingot so formedis substantially uniform baldness-throughout and has no large crystals with attendant crystal planes, and as a consequence produces a much ()r the smaller fpercemtage of dust or fines in crushing to orm commercial granulated carbid. With the admixture of solid carbid, the temperature of the whole mass is lowered to about the melting point of carbid with the result that there can be but little temperature differential between the exterior and the interior of the block during the act of solidification, and consequently thereis little or no opportunity for-segregation, develop ment of mation o voids. l Vhere, as usual in the'art, the exterior of the superheated mass of molten carbid is. allowed to cool and become hard. while the interior remains heated and freely molten forua relatively long period, all the contraction dueto solidification is accumulated at the center where there is apt to be a void or hollow space. -In the present invention, there being no opportunity for segregation or separation of difierent kinds of crystals the interior is of the samenature and hardness as the exterior.

Theadmixture of molten and solid carbid may be performed in any desired manner ronounced crystallization or forand with the use of'any desired apparatus;

such as those used in the manufacture of glass, may be employed for this purpose.

- The product produced as described and stirred, kneaded or agitated in the presence of solid carbid, upon solidifying instead of being pronouncedly crystalline in structure is characterized by a texture which in appearanceds lilfe that of porcelain or flint; that .is, it is finegrained, dense and homogeneous. In the practical use of the carbid this textureis advantageous since the absence of crystals and crystal planes offers no avenue for the penetration-of moisture during storage or during the operation of forming acetylene. With a coarsely crystalline aggregate, the crystalline planes offer an avenue for thb penetration of water. It is substantially desirable in making acetylene that the action of the water he confined to the exterior of a granule of calcium carbid and shall be strictly proportionate to the surface offrcd by such exterior.

What I claim is 1. In the manufacture of carbid, the process which comprises producing a fused body of carbid and mixing therewith'hardened particles of carbid.

2. 'In the manufacture of calcium carbid, the process which comprises producing a fused body of calcium carbid and mixing therewith hardened particles of calcium carbid.

v lar material, and mixing said fines wit molten carbid.

4. In the manufacture of calcium carbid, the process which comprises crushing a body of solid calcium carbid and'separatin'g into fines'and granular material, and mixingsaid fines with molten calcium, carbid.

5. In the manufacture of carbid, the rocess which comprisesproducing a fused ody of carbid and mixing therewith hardened particles of carbid, the mixture being stirred during the solidification of said fused body. 6. In the manufacture of calcium carbid, the rocess which comprises producing a fused bod of calcium carbid'and mixmg therewith ardened articles of calcium carbid, the mixture being stirred during the solidification of said fused body.

7 In the manufacture of carbid, the process which comprises crushing a body of solid carbid and separating into fines and granular material, and mixing said .fines with molten carbid, the mixture being stirred during the solidification of said fused body."

8. In the manufacture of calcium carbid, the process which comprises crushing a body of solid calcium carbid and se aratlng into fines and granular material, an mixing said fines with molten calcium carbid, the mix ture being stirred during the solidification of said fuse body. v

9. In the manufacture of carbid, the rocess which comprises forming an ingot 0 carcarbid.

and during such introduction stirring fine bid by gradual introduction of molten carbidinto a mold and during such introduction. stirring fine solidcarlnd into the molten 10. In the manufacture of calcium carbid, the process wh1ch com rises forming an in got of calcium carbid y gradual introduc tionof molten calcium carbid into a mold solid calcium carbid into the JIlOltGIl carbid.

11. As an article of manufacture, a body ,of ,solid carbid comprising solid particles of preformed carbid embedded in and cemented together by carbid solidified in place.

12. As an article of manufacture, a body v of solid calcium carbid comprisin solid articles of preformed calcium carbi emb dedin and cemented together by calciuincarbid solidified in place. i

p 13. As an article of manufacture, a' body of solid carbid comprising angular frag- Y ments of preformed carbid embe d ed in andv cemented together by a matrix of carbid. 

